be the biggest triumph of the country in the fight at sea. To give an idea of the radical change of German strategy in the two conflicts, only 375 U-boats (how was called the German submarines) were used in the WWI, against 1153 used in the WWII. Thus, it was in the second war that the German submarines gained prominence. German submarines surrounded the fleet that traveled in the North Atlantic. The investment of Nazi Germany in U-boats was directed at weakening the United Kingdom, always with its powerful navy, which at that time had no equivalent in the seas. It was necessary, then, to seek an alternative to defeat this naval power.